package com.rongxue.utils;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.JavaType;
import com.fasterxml.jackson.databind.ObjectMapper;

import java.util.List;
import java.util.Map;

/**
 * 自定义json工具类
 */
public class JsonUtils {

    // 定义jackson对象
    private static final ObjectMapper MAPPER = new ObjectMapper();

    /**
     * 将对象转换成json字符串。
     * <p>Title: pojoToJson</p>
     * <p>Description: </p>
     *
     * @param data
     * @return
     */
    public static String objectToJson(Object data) {
        try {
            String string = MAPPER.writeValueAsString(data);
            return string;
        } catch (JsonProcessingException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 将json结果集转化为对象
     *
     * @param jsonData
     * @param beanType
     * @param <T>
     * @return
     */
    public static <T> T jsonToPojo(String jsonData, Class<T> beanType) {
        try {
            T t = MAPPER.readValue(jsonData, beanType);
            return t;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 将json数据转换成pojo对象list
     * <p>Title: jsonToList</p>
     * <p>Description: </p>
     *
     * @param jsonData
     * @param beanType
     * @return
     */
    public static <T> List<T> jsonToList(String jsonData, Class<T> beanType) {
        JavaType javaType = MAPPER.getTypeFactory().constructParametricType(List.class, beanType);
        try {
            List<T> list = MAPPER.readValue(jsonData, javaType);
            return list;
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * 将json转化成map
     *
     * @param jsonData
     * @param beanType
     * @param <T>
     * @return
     */
    public static <T> Map jsonToMap(String jsonData, Class<T> beanType) {
        JavaType javaType = MAPPER.getTypeFactory().constructParametricType(List.class, beanType);
        try {
            Map<Object, Object> map = MAPPER.readValue(jsonData, javaType);
            return map;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * json转map
     * @param jsonObject
     * @param beanType
     * @param <T>
     * @return
     */
//    public static <T> T jsonToBean(JSONObject jsonObject, Class<T> beanType) {
//        JsonConfig config = new JsonConfig();
//        config.setJavaIdentifierTransformer(new JavaIdentifierTransformer() {
//            @Override
//            public String transformToJavaIdentifier(String str) {
//                char[] chars = str.toCharArray();
//                chars[0] = Character.toLowerCase(chars[0]);
//                return new String(chars);
//            }
//        });
//        config.setRootClass(beanType);
//        T p2 = (T) JSONObject.toBean(jsonObject, config);
//        return p2;
//    }
}
